This invention relates to methods for generating a calibrated projection and to apparatuses for generating a calibrated projection.
The use of projection systems for projecting an image onto a projection surface is common practice in many fields of industry, research and teaching. The projection of the image typically is effected onto a planar projection surface, e.g. a screen or an outer or inner wall of a building. From the prior art it is also known to use a plurality of projectors, with each of which partial images of a total image are projected. Such multi-projector system is described for example in DE 102 51 217 B3.
Multi-projector systems also are used for redundancy reasons, for increasing the luminous intensity or for increasing the resolution. For example, applications of such projector systems can be found in the field of architecture and/or generally in the field of CAD, in order to be able to in particular also represent details and/or also large models. The projectors of a multi-projector system must, however, be aligned (“calibrated”) relative to each other and/or relative to the projection surface such that a rather distortion-free image which appears correct to a viewer is generated. In particular, the projected partial images of the various projectors are adapted to each other and/or to the projection surface in a pixel-accurate manner (“stitching” or “warping”). Furthermore, the brightness of the partial images can be reduced in an overlap region with an adjacent partial image, in order to avoid that the total image has a greater brightness in such overlap regions.